The present invention relates to a laminated armature core structure which has comparatively less number of slots and longer teeth generally used for a small electric motor such as a windshield motor for a vehicle. The armature core used for such a small motor has substantially large slot area relative to the whole area of the core. Conventional method of making such core sheets or laminated core structure such as disclosed in U.S. Pat. No. 3,225,424 would merely remove the material from the slot area with a resultant substantial waste of material.